Making a quiz

[Qamar]

Hi, i'm taking a gr. 11 computer information science course and i need help plz. =)

Our teacher has told us to make a multiple choice quiz that has 30 questions and it randomly selects 25 of those questions then tells us what % of a mark we got... and he's barely taught us anything.. can anyone help me here .. or where to even start ?

thanks

[Tony]

you start with making a "quiz" made up of one question, then place that into a 25 step loop. If you do it right, there is _very little_ code that you need to write.

[Qamar]

okay... i see how you saying to do this... but i don't have a clue on how to.. haha. like i said. our teacher hasn't taught us much and is expecting us to know stuff

this is my code so far... he said its okay to have them in the terminal window. but he'd give us more marks if we could get them in a dialog box or make an applet with radio buttons

import java.io.*;

public class Quiz {
public static void main(String[] args) throws IOException {
//Create instances of the InputStream and BufferedReader
InputStreamReader reader = new InputStreamReader(System.in);
//Buffer the inputstream
BufferedReader buffer = new BufferedReader(reader);

float mark = 0;
float percent = 0;
String seeker;

System.out.println("Welcome to Qamar and Matt's Java Quiz...");
//Reference the buffer.readLine() command to seeker to grab the input
//Must use the equals method to compare strings == is invalid
//seeker.equalsIgnoreCase(String) takes input regardless of lowercase and uppercase so m is equal to M

System.out.println(" ");
System.out.println("Question 1");
System.out.println("What does OOP stand for ??");
System.out.println("A. Object Oriented Programming");
System.out.println("B. Official Organized Police");
System.out.println("C. Origins of Packets");
System.out.println("D. It doesn't stand for anything");
seeker = buffer.readLine();

if(seeker.equalsIgnoreCase("a"))
{
mark = mark+ 1;
}

System.out.println(" ");
System.out.println(" ");
System.out.println("Question 2");
System.out.println("Which line of code prints out words");
System.out.println("A. Print.String.");
System.out.println("B. System.out.println");
System.out.println("C. system.out.println");
System.out.println("D. That's RIDICULUS");
seeker = buffer.readLine();

if(seeker.equalsIgnoreCase("b"))
{
mark = mark + 1;
}
percent = mark / 2 ;
percent = percent * 100;
System.out.println("your score is: " + mark + " out of 2 which is " + percent + "%");

}
}

Quote:

[CooKieLord]

1. It would be awesome if you posted your code in [code] [/code] tags.
2. I would super-impose two arrays. One would be your bank of questions, and the other would be your answer key.

[Euphoracle]

Doing it the way you are doing it will leave you with 1000+ lines that someone else (this is was Tony was getting at) can do in about ~30 give or take line breaks. If your teacher thinks this is the best way of doing it, then you're going to have a serious problem next year. If you haven't consulted your teacher, do so. Don't be afraid to show your teacher your abilities and ask them for suggestions on how to improve. If you teacher has any capabilities in this subject, he/she should be able to help you change your code from what it is now (repetitive and unnecessary) to efficient and dare I say it, short.

[Barbarrosa]

Here are some recommendations, if you have to do this the hard way (you'll end up with < 300 lines, < 100 if you're fairly good, < 50 if you do the easy way well)

Assumptions to fill (for the hard way):

1. Is a specific number of possible answers given to all questions?
2. Terminal or GUI App?
3. Quiz loaded from file or embedded in program?
A. If from file, how to expect input? Make a file organized as such.
B. If embedded, how to create it
C. If embedded, whether you need to make a serious quiz, one with varying questions, or just show that you can use java
to make one.
4. Is the user always assumed to give valid input? (protecting from bad input could save you a lot of trouble)
5. If GUI, is there a next button, or is it automatically changed when an option is selected?
6. How should the final output be organized (GUI or terminal)?
A. Grade: 100%, 98.6%, 14.54% ?
B. List Answers to Questions?
C. Other Information?

Recommended classes to use:

Reading in from file: BufferedReader/InputStreamReader
Reading from terminal input: Scanner
Formatting Numbers: java.text.NumberFormat
GUI: Anything in java.awt.* or javax.swing.* (latter contains lightweight components)

[Qamar]

hey... so i won't lie.. i don't know what half of those mean... all i know is that i'm going to do it in a terminal window, teacher said he'd give us more marks to get it done in a dialog box but this project is already like 2 weeks past due. could someone help me here ? how do i create a random generator that would make numbers between 0 - 30 and only pick 25 ?

code:

import java.io.*; import java.util.Random; public class MCE {       public static void main(String[] args) throws IOException {       InputStreamReader reader = new InputStreamReader(System.in);        BufferedReader buffer = new BufferedReader(reader);            String[] Qs = {"An object...","Objects preform actions by executing...", "An Object..."};      String[] As = {"A) Represents useful data.","A) Methods.", "A) Represents useful data" };      String[] Bs = {"B) Preforms actions.","B) Actions", "B) Perfroms Actions"};      String[] Cs = {"C) Both A and B.","C) Procedures", "C) Both A and B"};      String[] Ds = {"D) None of the above.","D) Events", "D) None of the above"};             String seeker;       int cntr = 0;       float mark = 0;       int Qcount = 0;       float percent = 0;                   while (cntr < 3){      System.out.println (Qs[r]); // r is the variable that will produce a random number thingy.?      System.out.println (As[r]);      System.out.println (Bs[r]);      System.out.println (Cs[r]);      System.out.println (Ds[r]);      seeker = buffer.readLine();      Qcount = Qcount + 1;      cntr = cntr+1;            /*if(seeker.equalsIgnoreCase("c"))           {               mark = mark + 1;             }        */     percent = mark / Qcount;     percent = percent * 100;     percent = Math.round (percent);     System.out.println("Your score is: " + mark + " out of " + Qcount + " which is " + percent + "%");        }       }     }

[Barbarrosa]

code:

import java.util.Random; ... Random rand = new Random(); int[] randInts = new int[25]; for(int i = 0; i < 25; i++)        randInts[i] = rand.nextInt(30) + 1;

[Nick]

Barbosa, two errors.

1: 30 + 1 = 31 > max questions

2: say it picks 3 twice, that's not very professional

[Barbarrosa]

Sorry, woops. Wrong assumptions. This will give you 25 numbers, each between 1 and 30, none equivalent to the next, in an int array.

code:

import java.util.Random; ... //begin method Random rand = new Random(); int[] randInts = new int[25]; int recI = 0; for(int i = 0; i < 25; i++){        recI = rand.nextInt(30) + 1;  //You'll probably want it to remove the +1 if you're using an array to store questions, because an array starts at zero        if (arrayContains(randInts, recI)){               i--;               continue;        }        randInts[i] = recI; } return randInts; //end method private boolean arrayContains(int[] a, int i){        for(int o = 0; o < a.length; o++)               if(i == a[o])                      return true;        return false; }

Quote:

Barbosa, two errors.

1: 30 + 1 = 31 > max questions

2: say it picks 3 twice, that's not very professional

1. Random's nextInt(int) method returns an integer between 0 & int-1

2. Fixed here. I wish the arrays in java had a contains(int) method.

[Qamar]

okay that is sick... but could you tell me how to implement that into my code ?. haha i've spent my whole comp. sci class (75mins) trying to get it to work... but with no success

[Barbarrosa]

1. Give more significant names to your variables, even if they are longer
These don't make much sense:

String seeker;
int cntr = 0;
int Qcount = 0;

What's seeker doing in a quiz program? What's cntr? Why is Qcount capitalized, and why isn't numQuestions or questionCount used?

2. Use for statements like:

code:

for(T i:T[]){} // T represents the type - int, float, String, etc. Replace T[] with an array of that type. for(int i = 0; i < array.length;i++){}

3.Use methods to divide up complex tasks:

code:

private boolean intArrayContains(int[] a, int i){        for(int o = 0; o < a.length; o++)               if(i == a[o])                      return true;        return false; }

4. Explore the javadocs online - java has classes and interfaces for lots of things.

java.util.Scanner
java.text.NumberFormat

[Qamar]

okay cool... so i've explored some different stuff and i decided to put everything into an array... my only problem is i don't know how to set parametors on the random integer and also so that it won't repeat the same quesitons... my code so far is

code:

/**  * A quiz that asks you  25 questions randomly out of 30  * By: Qamar, Matt and Steven  */ import javax.swing.*;// imports the superclass that allows for use of GUI import java.util.Random; //import java.io.*; public class Quizrr { // public static void main(String[] args) {//            String[] Qs = {"An object...","Objects preform actions by executing...", "Which line of code is correct?","What does OPP stand for ?"};      String[] As = {"1) Represents useful data.","1) Methods.", "1)System.out.PRINT ","1) Official Programming Protocol" };      String[] Bs = {"2) Preforms actions.","2) Actions", "2) SYSTEM.out.Print","2) Object Oriented Programming"};      String[] Cs = {"3) Both A and B.","3) Procedures", "3) system.Out.Print","3) Ontario Programming Police"};      String[] Ds = {"4) None of the above.","4) Events", "4) System.out.print","4) Objective Protocol Packets"};        int [] answer = {3,2,4,2};         int count = 0;     String ans;     float mark = 0;     float percent = 0;     int ans2 ;             while (count < 4) {             Random r = new Random();             int randint = r.nextInt(4); // this will pick 1 less than what is in the brackets (n - 1)                     ans = JOptionPane.showInputDialog("" + Qs[randint] + "\n"             +"" + As[randint] + "\n"             +"" + Bs[randint] + "\n"              +"" + Cs[randint] + "\n"              +"" + Ds[randint] + "\n" );             ans2 = Integer.parseInt(ans);                     if (ans2 == answer[randint])                             {             mark = mark+ 1;         }         count = count + 1;     } // end loop         percent = mark / count; percent = percent * 100; percent = Math.round (percent); JOptionPane.showMessageDialog(null,"Your score is: " + mark + " out of " + count + " which is " + percent + "%");// diplays a pop-up that has the final information                } // end method         } // end class

and yeah. everything is okay except for the random integer selection... i saw the code from before... but i don't understand the rest of it

[wtd]

Try to use an array of objects rather than parallel arrays.

[Qamar]

okay. never mind. my teacher said that it would be a better idea if i could just shuffle the arrays at the beginning of the program so that they don't go in order each time... how would i do that ? and keep the Questions and answers and possible answers the same ?